A capacitor around the periphery of the CPU (Central Processing Unit) for use in personal computers and the like has been demanded to have high capacity and low ESR (equivalent series resistance) in order to suppress voltage variation and to keep the heat generation during the passage of a high ripple at a low level. As such a capacitor, an aluminum solid electrolytic capacitor, a tantalum solid electrolytic capacitor, and the like have been used. As these solid electrolytic capacitors, a capacitor is known which is constituted of one electrode (anode body) containing a sintered body obtained by sintering an aluminum foil having fine pores in a surface layer or tantalum powder having fine pores therein, a dielectric layer formed on the surface of the electrode, and another electrode (usually a semiconductor layer) formed on the dielectric layer.
As the solid electrolytic capacitor, a method is known which includes electrically connecting one end of a lead wire extended from the anode body to a metallic connection terminal of a socket attached to a lower end portion of a circuit board on which electrical circuits are formed and immersing the anode body in a chemical conversion treatment liquid, applying a voltage, while using the anode body side as an anode, between the anode and a cathode disposed in the chemical conversion treatment liquid to apply a constant current to thereby form a dielectric layer on the surface of the anode body, immersing the anode body on the surface of which the dielectric layer is formed in a semiconductor layer forming liquid, applying a voltage, while using the anode body side as an anode, between the anode and a cathode disposed in the semiconductor layer forming liquid to apply a constant current to thereby further form a semiconductor layer on the surface of the dielectric layer on the surface of the anode body (Patent Document 1).